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25-Gb/s broadband silicon modulator with 0.31-V·cm VπL based on forward-biased PIN diodes embedded with passive
Optics Express
|February 3, 2016
Summary
We developed a silicon Mach-Zehnder modulator (MZM) using a forward-biased PIN diode and passive equalizer. This device achieves 17 GHz bandwidth and 25 Gb/s operation, demonstrating broadband performance for optical communications.
Area of Science:
- Photonics and Optical Engineering
- Semiconductor Device Physics
Background:
- Silicon Mach-Zehnder modulators (MZMs) are crucial for optical communication systems.
- PIN diodes offer modulation capabilities but often suffer from narrowband frequency responses.
Purpose of the Study:
- To investigate broadband operations of a silicon Mach-Zehnder modulator (MZM).
- To compensate for narrowband characteristics of PIN diodes using a passive-circuit equalizer.
Main Methods:
- Fabrication of a silicon MZM using standard CMOS processes.
- Integration of a forward-biased PIN diode with a passive-circuit equalizer comprising doped silicon resistance and metal capacitance.
- Characterization of device performance including VπL and 3-dB bandwidth (f(3dB)).
Main Results:
- Achieved a low VπL of 0.31 V·cm.
- Demonstrated a flat frequency response with a 3-dB bandwidth (f(3dB)) of 17 GHz.
- Obtained 25 Gb/s large-signal operation using binary signals without pre-emphasis.
Conclusions:
- The integrated passive-circuit equalizer effectively compensates for narrowband diode characteristics.
- The silicon MZM exhibits linear modulation properties and broadband performance suitable for high-speed optical communication.
- Standard CMOS fabrication ensures a simple and scalable device structure.
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